NT Labs Test Nitrite (NO2) is an aquarium water testing kit used to measure nitrite (NO₂) levels in freshwater or marine tanks.

What is nitrite?
Nitrite is produced by beneficial filtration bacteria as they break down the harmful waste ammonia excreted by the fish. Like ammonia, it is not visible to the naked eye. Nitrite is still very damaging to the health of the fish although it is not visible to the naked eye. Nitrite is then broken down into nitrate, which is harmless to the fish.

What is the recommended nitrite level?
A level of zero mg/L (ppm) should be maintained at all times.

What do I do if the Nitrite level is wrong?
If a level above 0.25 – 0.5 mg/l (ppm) of nitrite is recorded, then a substantial water change is essential. Change 25% of the water volume for 1 mg/l (ppm) nitrite and 50% for nitrite levels above this. If you record nitrite levels, it is important to check other vital water quality parameters, especially pH and ammonia.

How to use?

• Ensure the test tube is clean.
• Take a 5 ml sample of water into the test tube.
• Add 5 drops of the Nitrite reagent.
• Replace the test tube cap and shake thoroughly.
• Wait 2 minutes, then compare the colour of the sample to the colour scale provided. Zero nitrite is represented by a colourless sample. Any hint of pink in the sample indicates the presence of nitrite in the water. Any colour forming after the two minutes should be ignored.